The subject invention relates to medical electrodes, and more specifically, to such electrodes which are used in combination with stimulation iontophoresis, monitoring, or grounding equipment. As such, these electrodes are intended to provide an electrical connection to the skin when attached to the skin surface of humans and animals.
Prior skin interface electrodes, typically, have comprised a skin interfacing member such as a gum pad, gel saturated sponge, gel layer or adhesive layer, wherein, in each instance, this interface member has been electrically conductive. A current distribution or collecting member had formed a backer to the interface member. Typically, this backer member was constructed of a metallic sheet of material or a carbon impregnated sheet of material, or the like, the distribution and collecting backer member being also electrically conductive. A snap connector was attached to this distribution and collecting member and had been used to establish an electrical connection with the distribution and collecting backer member. A female snap mating part was engaged complete an electrical circuit to a remote piece of equipment.
As alternative to the snap connector, the electrical connection has been completed to the distribution and collecting backer member by soldering or welding a section of electrical wire to that member, this electrical wire having a banana plug connector on its free end.
In some instances, a diffusion screen was utilized and positioned within an interfacing pad when this pad was of greater thickness. Typically, such a diffusion screen was positioned midway through the pad, and while not a necessary part of the electrode, it acted to further equally distribute current densities throughout the pad which resulted in more uniform current densities at the skin contact surface.
Electrical connection to the electrodes involved either the snap connector or the solder or weld joint with a disparate banana plug or other connecting pins or sockets. In the first instance, the snap connector was mated to the electrically conductive backing material (distribution and collecting member) and became permanently affixed thereto. This snap connector provided a very high profile and a sharp pressure point wherein individual electrodes may not be stacked upon one another in storage without protection of adjacent electrodes from the piercing by the adjacent snap connector. This protruding snap connector also represented a hazard to the patient if he should roll on it.
In order to provide an efficient and effective electrical connection, the ball or head of the mating portion of the snap connector must fit tightly with its mating member. As such, relatively large stresses are placed upon the backing member to which the snap connector is attached when the snap connection is made or broken. This results, very often, in a ripping of the backing material and a dislodgement of the snap connector.
The electrode configuration using the soldered or welded wire end, on the other hand, provides a concentrated stress point which often results with a broken solder joint or weld joint or a broken wire at the solder or weld point. Likewise, very often the weld point is pulled apart by the stresses exerted on the wire during everyday use, the backing material very often being quite thin and possessing little mechanical strength.
An object of this invention is to provide an electrode structure which has a very low profile and presents no sharp protrusions.
A second object of this invention is to provide such an electrode utilizing a gum interface substrate and also a backer structure which is quite pliable, this backer structure having a stranded or filament configuration which quite easily conforms to any configuration to which the gum substrate is shaped.
A further object of this invention is to provide such an electrode wherein the electrically conductive backer material which distributes or collects electrical signals across the entire surface of the gum interface substrate is of an open-weave mesh or screenlike material, this material adhering to a surface area of the substrate.
An additional object of this invention is to provide such an electrode wherein an additional material is sewn to the open-weave backer, this material providing a large area connection surface for the mating of a connector apparatus.
An even further object of this invention is to provide such an electrode wherein the large area connection surface includes a looped pile material and the mating connector includes pile loops interlocking hooks.